Medical device systems are being developed for long-term treatment of chronic conditions. Because of the nature of chronic conditions, patients may need to carry a medical device on their person regularly. For example, ventricular assist devices (“VADs”) to treat chronic heart failure may be fully implantable and thus carried by the patient at all times. Similarly, drug pumps may be carried on a patient, either fully implanted or with transcutaneous components, to provide medicine as necessary to treat a condition. These include, for example, fully or partially implantable insulin pumps that deliver insulin from a medicinal reservoir in the device to the body to the patient to manage diabetes.
These types of medical devices often have controllers that store information and provide some level of automation to the medical device. For example, in addition to a VAD, a medical device system may include a handheld controller outside the body connected to the VAD via a wired connection, such as a transcutaneous electrical cable, or via a wireless connection. The controller may provide operating instructions to the VAD and store information relating to current and past operation of the VAD as well as physiological data sensed by the VAD. Other medical devices may work similarly. For example, insulin pumps may include a controller portion separate from an insulin containing and pumping mechanism. In both cases, patients may have one or more backup or secondary controllers so that, in the event of failure of a primary or active controller, the patient may disconnect the failed controller and replace it with a backup controller to provide continuity of treatment.
Although there may be varying levels of criticality to continuity of treatment, in most cases it is desirable to have the medical device return to full functionality as soon as possible following failure of the controller. In the case of a VAD, this may be highly critical. If a VAD controller suffers catastrophic failure, operating instructions and/or power to the VAD may be interrupted, in turn interrupting sufficient blood flow to the patient. For insulin pumps, perhaps potentially less critical, a failed controller may limit or completely hinder the patient from receiving any basal and/or bolus deliveries of insulin, potentially putting the patient at serious risk of a hypoglycemic event.
As medical device technology develops, controllers of medical devices may provide more complex and effective control of the medical device. Further, the controllers may store a broad range of information, such as device and patient health information. As the patient's experience with use of the medical device grows, controllers may be updated to deliver more optimal control and may acquire more data relating to operation of the medical device system and/or parameters of the patient, such as pressures experienced in the heart or glucose levels existing in the blood.
If a medical device controller is updated, for example by a clinician to provide different operating instructions, or by the accumulation of historical data, those updates are generally stored only within the controller connected to the medical device. If failure of the controller does occur and a backup controller is connected to the medical device in place of the failed controller, the newly connected controller will not have all of the same information stored in its memory. Thus, important information may be lost and the operation of the medical device under the control of the newly connected controller may be different than the operation of the medical device under the previous controller before it failed or was switched out for a secondary controller.